1. Sub-selector
The front and back parts of the sub-selector are separated by a greater than sign. The two parts of the selector are structurally a parent-child relationship.
The child selector is based on the parent element specified by the left selector, and then looks for child elements matching the right selector under the parent element.
2. Simple example
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>子选择器</title><link type="text/css" rel="stylesheet" href="css/demo5.css"/></head><body><div> <p>这是个段落 <a href="#">这是超连接</a> </p></div></body></html>
@charset "utf-8";/* CSS Document *//*设置div下的p元素的样式*/div>p{ font-size:14px; color:#0000FF; }/*设置p元素下的a元素的样式*/p>a{ font-size:16px; color:#FF0000; text-decoration:none;}/*错误的写法 div 与a不是父子关系时,是取不到的*/div>a{ font-size:20px; color:#FF0000; text-decoration:none;}
The sub-selector is very Rarely used, generally use containing selections that are not affected by the parent-child relationship
The following writing contains the selector
div a{ font-size:20px; color:#FFFF00; text-decoration:none;}

The official account web page update cache, this thing is simple and simple, and it is complicated enough to drink a pot of it. You worked hard to update the official account article, but the user still opened the old version. Who can bear the taste? In this article, let’s take a look at the twists and turns behind this and how to solve this problem gracefully. After reading it, you can easily deal with various caching problems, allowing your users to always experience the freshest content. Let’s talk about the basics first. To put it bluntly, in order to improve access speed, the browser or server stores some static resources (such as pictures, CSS, JS) or page content. Next time you access it, you can directly retrieve it from the cache without having to download it again, and it is naturally fast. But this thing is also a double-edged sword. The new version is online,

This article demonstrates efficient PNG border addition to webpages using CSS. It argues that CSS offers superior performance compared to JavaScript or libraries, detailing how to adjust border width, style, and color for subtle or prominent effect

The article discusses using HTML5 form validation attributes like required, pattern, min, max, and length limits to validate user input directly in the browser.

The article discusses the HTML <datalist> element, which enhances forms by providing autocomplete suggestions, improving user experience and reducing errors.Character count: 159

The article discusses the HTML <progress> element, its purpose, styling, and differences from the <meter> element. The main focus is on using <progress> for task completion and <meter> for stati

Article discusses best practices for ensuring HTML5 cross-browser compatibility, focusing on feature detection, progressive enhancement, and testing methods.

The article discusses the HTML <meter> element, used for displaying scalar or fractional values within a range, and its common applications in web development. It differentiates <meter> from <progress> and ex

The article discusses the <iframe> tag's purpose in embedding external content into webpages, its common uses, security risks, and alternatives like object tags and APIs.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

Atom editor mac version download
The most popular open source editor

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.
